Let me provide my contribution to this discussion around this ZOS port
topic :
I initially made the Python 2.2 and 2.4 for ZOS platform and ask the
python community to link to my pages as a support to ZOS at that time 

Lauri get in touch with me couple of weeks ago asking if I was planning
to make a port of the 2.5 ; since I was waiting for 2.6 before
initiating a new port, He goes ahead and makes the 2.5 port happen now.

About how important is the ZOS system ; let me argue around that :  even
if ZOS is an IBM proprietary OS which
has been there for decades it will be there for a long time since it
occupies a very specific 'niche' on the os'es market 
And since IBM has heavily spoiled the migration path to Unix in order to
keep its revenues on it migrating those 
systems to plain vanilla unixes is a nightmare => Today every US or
European big company s having a ZOS sytem somewhere. 
Next even if ZOS is proprietary and EBCDIC it has a peasonable POSIX.5
compliant subsystem and a descent C/C++ compiler
which makes the port of python not too complex.

From a script standpoint there are today 3 available scripting languages
availables :
- REXX (the mike cowlishaw script language) , perl and python)

So keeping an accurate version of python on this platform makes sense as
well to increase the python language usage

Next I am still happy  to continue supporting the ZOS port and I
perfectly understand that fully integrating the ZOS idiosynchrasies 
into the Python main branch generates maintenability problems ... But
some of the submitted problems included into Lauri patch are not ZOS
specific and increase 
and simply increase the portability of the python Kernel  to EBCDIC
platform(ZOS and OS400) 

So finally my opinion here is the the problem can be splitted into two
parts :

1 General improvements patches which improves the Python kernel which
can be incorporated in the python kernel and which 
may not be to complicated to maintain on the main branch

2 ZOS idiosynchrasies (mainly located in making the autoconf/automake
and build scripts compliant with ZOS ); this can be done specifically by 
zos python specialists which have access to ZOS mainframe in order to be
able to test.

I am happy to continue to make the topic 2 availables on the ZOS python
port pages with the help of others contributors like Lauri and 
give them credit on the ZOS port page. So I propose to integrate lauri's
patch in the 2.5.1 current and provide a modified ZOS compliant 
source tar containing modified autoconf/automake and dynamic loading stuff

I Finally should emphazise on 2 complementary arguments : 

- The ZOS port has been used in industrial products(including the
company for which I work today) and contributes to promote 
the python language on important non unix platforms showing the extreme
portability of the language.
- Even the IBM Labs in Boulder(colorado) get in touch with me in order
to integrate the port in one of their project.